There may be various radio network problems occur during the access of a user equipment (UE) to a radio network, for example, radio link failure (Radio Link Failure, RLF) or handover failure (Hand Over Failure, HOF), Handover Too Early, Handover Too Late, ping-pong handover.
When an RLF occurs on the UE, the UE re-establishes a radio resource control (Radio Resource Control, RRC) within a specified time; if the re-establishment fails within the specified time, the UE may initiate an RRC establishment request subsequently; when the UE receives a handover command and fails to perform a handover within the specified time, that is, an HOF occurs, the UE may perform an RRC re-establishment procedure within a specified time. Similarly, if the re-establishment fails within the specified time, the UE may also initiate an RRC establishment request. In addition, when an RLF occurs on the UE, a cell where the UE camps before the RLF occurs is referred to as a previous serving cell (P-Cell), and other cells are uniformly referred to as new cell (N-Cell). However, when an HOF occurs on the UE, because the handover concept is involved, there are three types of cell: source cell (S-Cell), target cell (T-Cell), and other cell (O-Cell).
For example, when an RLF occurs on a UE, a procedure of RRC re-establishment or establishment is shown in FIG. 1. The procedure includes the following steps.
1. An RLF occurs on the UE.
2. The UE initiates an RRC connection re-establishment or establishment procedure.
Specifically, the UE may perform the RRC connection re-establishment in the P-Cell or the N-Cell; or after the RRC re-establishment fails, the UE may initiate a subsequent RRC establishment procedure in the P-Cell or the N-Cell.
FIG. 2 is a schematic diagram of an RRC re-establishment or establishment procedure when a UE performs a handover and an HOF occurs. The procedure includes the following steps.
1. A source cell (S-Cell) performs measurement configuration on the UE.
2. The UE performs corresponding measurement.
3. If a result of the measurement meets a set condition, the UE reports a measurement report to the S-Cell.
4. The S-Cell decides to hand over the UE to a target cell (T-Cell) according to the measurement report reported by the UE.
5. The S-Cell sends a handover request message to the T-Cell.
6. The T-Cell returns a handover response message to the T-Cell.
7. The S-Cell sends a handover command to the UE.
8. In this case, if the radio signal of the T-Cell is not good, the UE may not hand over to the T-Cell within a specified time.
9. After a timer set on the UE side expires, an HOF occurs on the UE. In this case, the UE may initiate an RRC connection re-establishment procedure.
Specifically, the UE may perform the RRC connection re-establishment procedure in an S-Cell or a T-Cell or an O-Cell of a previous handover, where the O-Cell is a cell other than the S-Cell and the T-Cell; or after the RRC connection re-establishment fails, the UE initiates a subsequent RRC connection establishment procedure. Similarly, the RRC connection establishment procedure may also be performed in the S-Cell, the T-Cell or the O-Cell.
According to the solution in the prior art, no solution that can automatically identify and detect these radio network problems is available in the prior art. Consequently, various radio network problems such as Handover Too Early or Handover Too Late may occur due to parameter settings, so that call drops occur on the UE, therefore affecting a user experience.